Chronic pain is a poorly understood disorder that is accompanied by great personal suffering and substantial economic costs to society. The etiology of chronic pain is unknown, and the long-term objective of the proposed research is the identification of psychosocial antecedents and consequences of this disorder. Although chronic pain patients have been extensively studied, it has not been possible to determine whether the psychosocial characteristics of these patients are antecedents of their chronic pain or whether they have been caused by the experience of living with chronic pain. The primary aim of the proposed research is to identify psychosocial antecedents of a chronic pain syndrome using a prospective research design, and to distinguish such antecedents from concomitants and consequences of chronic pain. Herpes zoster, a viral disease in which a latent varicella virus is reactivated, provides a means by which this can be accomplished. Pain accompanies herpes zoster, and its duration varies widely among patients and is unremitting in a percentage of cases. Herpes zoster pain that persists beyond healing of the acute infection is a well-known chronic pain syndrome (postherpetic neuralgia) that is often accompanied by great disability and distress. In the proposed research, patients with acute herpes zoster will be assessed with respect to hypothesized psychosocial antecedents of chronic pain and will then be studied prospectively for one year. Periodic follow-up assessments of pain the selected psychosocial variables will allow antecedents of chronic pain to be identified and to be distinguished from its concomitants and consequences. The proposed research constitutes an important first step in understanding the processes involved in the development and maintenance of chronic pain. This knowledge is not only necessary in developing more effective treatments for chronic pain syndromes, but is also essential in formulating methods for the prevention of these disabling disorders.